How can i feed the output of the Dynamic Paint into the input of the Wireframe Node?
To get direct node access to the output of the Dynamic Paint you need to use the Paint Surface Type in the Dynamic Paint Advanced properties (in your example you appear to be using Weight). For 'Paint' surfaces the Dynamic Paint Output can be set to output to a Color Map Paintmap layer and this can then be accessed in the material nodes via an Attribute node set to the name of your Color Map.

For the Canvas object (the one receiving the paint), enable Dynamic Paint, select as Canvas and Add Canvas. Ensure the Surface Type is 'Paint' and in Dynamic Paint Output click the '+' button alongside the Wetmap layer to create the Color Map (wetmap allows 'drying'). To have the paint 'fade' when not near the 'brush', enable Dry. This will fade out the paint effect as if drying, until it returns to the original color. 



Note : Since the canvas is outputting to Vertex Colors, ensure your canvas mesh is suitably sub-divided.

For the Brush, enable Dynamic Paint and Add Brush and set the Paint Source to Mesh Volume and Proximity to allow it to affect nearby surfaces.



In your material, add an Attribute node and set it to the name of your Color Map as specified in the canvas Paintmap layer ('dp_wetmap' if you haven't changed it from the default). This can be used to affect the size of the Wireframe as shown :



This can produce the following results :



Blend file attached